W-type hexaferrite nanoparticles of nominal composition BaCo 2-xMn xFe 16-2yZr yNi yO 27 (x = 0-0.5; y = 0-1.0), are synthesized by using the chemical co-precipitation technique. The X-ray diffraction (XRD) data conform to the formation of single phase. Mössbauer analysis reveals that extrinsic substitution of metal ions (Mn x and Zr y-Ni y) takes place at 2d, f IV, 2b, and 12k sub-lattices. Doped metal substitution up to ionic contents of x = 0.3 and y = 0.6, results in enhancement of the saturation magnetization M s and remanent magnetization M r while these substitutions lower the coercivity H c. The optimum values of the above mentioned three parameters, measured at room temperature, using a vibrating sample magnetometer (VSM), are 79.7 emu g -1, 36.0 emu g -1 and 1012 Oe, respectively. Microwave absorption characteristics calculated from complex permeability and complex permittivity data retrieved by a vector network analyzer (VNA) increase as the doped metal ions content increases.
- A. Powders: chemical preparation
- C. Magnetic properties
- D. Ferrites
- Microwave absorption
- Mössbauer spectroscopy